I have selected some articles from the National Institute of Mental Health and the American Psychiatric Association. The statistics seem to vary; however, overwhelmingly - if you take an average of the estimates - the numbers seem to add up to over 20% (1:5) of the population having a diagnosable mental disorder.
According to the National Institute of Mental Health, "An estimated 26.2 percent of Americans ages 18 and older — about one in four adults — suffer from a diagnosable mental disorder in a given year."www.nimh.nih.gov/health/publications/the-numbers-count-mental-disorders-in-america/index.shtml
The article also states: "About 6 percent, or 1 in 17, suffer from a serious
mental illness." (It didn't specify which were considered serious and which were not. This article does not include BPD, NPD or AsPD in it's findings.)
A study published in 2004 in the Journal of Clinical Psychiatry summarizes that, "14.8% of Americans (30.8M adults) meet diagnostic criteria for at least one personality disorder." Not included in this study were BPD, NPD and Schizotypal PD's "due to the large number of symptom items required to diagnose those disorders." (Also noticeably missing was BiPolar Disorder.)www.pn.psychiatryonline.org/cgi/content/full/39/17/12
Obsessive Compulsive PD 7.9% (16.4M)
Paranoid PD 4.4% (9.2M)
Antisocial PD (Sociopath) 3.6% (7.6M)
Schizoid PD 3.1% (6.5M)
Avoidant PD 2.4% (4.9M)
Histrionic PD 1.8% (3.8M)
Dependent PD 0.5% (1M)
The US Department of Health also republished this report: www.nih.gov/news/pr/aug2004/niaaa-02.htm
I'm not entirely sure what "Schizotypal PD" is, and in Googling it, I can't find too much readily available. So let's just put that aside. But here are the statistics for the other 3 PD's not included in this report:
Psychiatric News, published by the American Psychiatric Association, summarizes that, "The lifetime prevalence of narcissistic personality disorder among American adults is 6%."www.pn.psychiatryonline.org/cgi/content/full/43/15/38
I can't find a good NIMH or APA article referencing this, but most sources estimate between 1 - 3%, with most stating 2% or 4M people.
Point of interest, another article states: "The prevalence of Borderline Personality Disorder is estimated to be about 2% of the general population, about 10% among individuals seen in outpatient mental health clinics, and about 20% among psychiatric inpatients. In ranges from 30% to 60% among clinical populations with Personality Disorders."www.borderlinepersonalitytoday.com/main/dsmiv.htm
From the same NIMH article listed above, "Bipolar disorder affects approximately 5.7 million American adults, or about 2.6 percent of the U.S. population age 18 and older in a given year."
So, adding all of that up: OCD, Paranoid, AsPD, Schizoid, Avoidant, Histrionic, Dependent = 14.8% Plus NPD, BPD and BiPolar = 10.6% for a grand total of 25.4% or 1:4 people in the US. For argument's sake, lets assume those numbers are high, and we subtract 5% off of that total for good measure. That puts the prevalence of PD's at 1:5 people. Let's assume that those numbers are WAY off, and we subtract 10% off the total prevalence. That STILL puts the prevalence of PD's at almost 1:6 people.
Look at this another way... Personally, I find the Cluster C PD's (BPD, NPD and AsPD) and BiPolar Disorder to be the least
readily identifiable of the PD's, and the most
destructive to the people that get involved with them. Just using those numbers:
BPD 2% (1:50)
NPD 6% (1:17)
AsPD 3.6% (1:28)
BiPolar 2.6% (1:38)
That's a total of 14.2% or 1:7 people have a pervasive, mostly incurable, destructive personality disorder, that has been known to wreak havoc in the lives of those around them... Take it a step further, and let's say that those NPD estimates are off (they seem to vary), and we'll use 2.5% for NPD to keep it amongst the average of the rest. That still puts the numbers at 10.7% or more than 1:10 people have a destructive PD.
When you think of the BPD estimates of being only 2%, it sounds small. But not when you consider that's the equivalent of one out of every 50 people in the US - and the majority of them are not in mental institutions. The scariest to me is the AsPD (Sociopath - no conscience) estimates of 3.6% or one in 28 people in the US. Granted, many of these people are locked up in prison - but certainly not the majority. Assuming that a full 1% percentage is locked up (that's a third of all AsPD's and is probably being generous) - that still leaves 1 out of every 38 people you come into contact with having absolutely no conscience, compassion, or sense of responsibility towards any other human on earth.
All of this is just some food for thought the next time you visit a dating website, get on an airplane, go to the mall, or look around your family dinner table.